1. Field of the Invention
The present invention relates to a reaction device including reactors such as a reformer, a carbon monoxide remover, which are used for a power generator such as a fuel cell device and the like, require a high operating temperature and are housed in a heat insulating container, a fuel cell device, and an electronic apparatus, the latter two using the reaction device.
2. Description of Related Art
In recent years, a fuel cell using hydrogen as a fuel has begun to be applied to a motorcar, a portable device, and the like as a clean power source having high energy conversion efficiency. The fuel cell is a device for taking out electric energy directly from chemical energy by reacting a fuel and oxygen in the atmosphere electrochemically.
As the fuel used for the fuel cell, hydrogen can be given, but the hydrogen has a problem of its handling and storage because the hydrogen is a gas at an ordinary temperature. If a liquid fuel such as alcohols and gasoline is used, there become needed a vaporizer
vaporizing the liquid fuel, a reformer taking out hydrogen necessary for electric power generation by reacting the liquid fuel and high temperature steam, a carbon monoxide remover removing carbon monoxide, which is a by-product of a reforming reaction, and the like.
Because the operating temperatures of the reformer and the carbon monoxide remover are high, they have been housed in a heat insulating container to suppress heat dissipation. Moreover, a reflection film reflecting infrared rays (having wavelengths of 0.7 μm to 1 mm) has been formed on the inner wall surface of the heat insulating container to reduce the loss of thermal energy to the outside (see, for example, Japanese patent application publication laid-open No. 2004-6265).
Moreover, the intake of the fuel and the discharge of a reformed gas into and from the carbon monoxide remover from and to the outside of the heat insulating container are performed through a pipe connected to the carbon monoxide remover. Accordingly, the junctions of the carbon monoxide remover and a vacuum chamber with the pipe are joined by filling with cement (such as glass frit in case of glass to glass, or a metal or an alloy having a lower melting point in case of metal to metal) (see, for example, Japanese patent application publication laid-open No. 2005-259354).
Now, to the wall of the heat insulating container, where the pipe of the reformer and the carbon monoxide remover penetrates, heat is conducted from the pipe of higher temperature. Consequently, a large temperature difference is caused in the wall of the heat insulating container between the neighborhood of the pipe and the other periphery thereof, and a large thermal stress reduces the strength of the junctions of the pipe.
It is one of objects of the present invention to reduce drastic temperature difference around the penetrated part of the wall by the pipe in order to reduce thermal stress in a reaction device in which a pipe penetrating the wall of a heat insulating container is connected to a reactor inside the container, so as to provide a safe reaction device, a fuel cell device and an electronic apparatus, the latter two using the reaction device.